PROJECT SUMMARY/ABSTRACT: An estimated 1 in 190 women carry a pathogenic variant in BRCA1/2, which is associated with an 46-57% risk of breast cancer and 20-40% risk of ovarian cancer by age 70. Carriers account for 10% and 15% of breast and ovarian cancer cases, respectively, and up to 20% of high- grade serous ovarian cancer cases, the most aggressive subtype. Despite recommendations that all ovarian cancer cases should receive genetic counseling and testing, irrespective of family history and age at onset, a recent national study indicated that only 10% of cases underwent genetic testing. This represents a missed opportunity to inform these women and their at-risk family members about their future cancer risk. The proposed study addresses this care gap by applying a traceback testing approach to retrospectively identify women who have a prior diagnosis of ovarian cancer. These women will then be offered genetic counseling, testing, and cancer risk assessment. This study will leverage tumor registries to identify prior cases of ovarian cancer diagnosed within the past 10 years at two managed care healthcare systems (Kaiser Permanente Northwest and Kaiser Permanente Colorado). The use of archived pathology samples for germline genetic testing will allow family members of both living and deceased women to receive familial genetic cancer risk information. We will assess: 1) the feasibility of and barriers associated with using tumor registries and archived pathology samples for a traceback testing approach; 2) explore the ethical, privacy, and policy implications associated with genetic testing in deceased patients to inform familial risk; 3) characterize barriers to receiving genetic counseling at the time of diagnosis, including barriers to referral, care access, and patient follow-up to. We have assembled a multidisciplinary team with expertise in bioethics, genetic epidemiology, genomic medicine, biostatistics, health communication, and medical genetics. We will engage patients, family members, providers, and health system administrators to guide study design and characterize barriers to genetic testing in ovarian cancer. Our unique integrated health information systems, tumor registries, and archived pathology specimens make us ideally suited to investigate the feasibility of traceback testing. Generating evidence on the feasibility of traceback testing using tumor registries and archived pathology samples is critically important to the guide future implementation of such programs beyond ovarian cancer.